questions concerning measurements, experiments, and activities that demonstrate physics and are safe to do at home, require at most one tool or ingredient not readily available, and can be interpreted or analyzed on one sheet of paper with accessible math.

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3answers
491 views

Beads in 'perpetual motion'?

This page has an interesting video of beads 'syphoning' out of a glass beaker: http://blog.zennioptical.com/weekly-optical-illusion-crazy-beads/ The host has a few explanations for the effect, but ...
29
votes
3answers
2k views

Floating a ping pong ball in the air just using a pen!

Caution: Apparently this problem is harder than it seems! There is a well known phenomena, which I first learnt about when I was a 10 years old kid. You can levitate a ping pong(or whatever ...
0
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1answer
210 views

Magnetic field, alternated current and EMF

If I apply an alternated current to a solenoid and insert into it a smaller solenoid, I could measure the induced EMF (electromotive force) and study how it changes in relation to the frequency of ...
-4
votes
3answers
232 views

Can you lift a basket up while standing inside it? [closed]

Suppose you stand in a basket and you try to pull the handles of the basket. Will you be able to lift the basket from ground? Similarly, Baron Münchhausen allegedly pulled himself and the horse on ...
10
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3answers
807 views

Best way to chill a cup of coffee with cold water and 5 minutes [duplicate]

Initial data 1 x 3/4 full cup of hot coffee / tea / your favorite morning beverage cold water 5 minutes Considering that it's starting to get hot outside, and we all want to drink reasonably cold ...
11
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2answers
468 views

The secret behind the spinning, asymmetrically weighted, 2D disk-shaped top?

When you spin an asymmetrically weighted, 2D disk-shaped top, the heavy part actually rises to the top. Why is this? http://www.youtube.com/watch?v=h0SZZTBQmEs ...
2
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1answer
73 views

Creating a stream of single file atoms

How do you go about creating a stream of single file atoms? The aim is to fire a stream of single file atoms (hydrogen, helium) down a vacuum and detect there arrival on the opposite end. Any ...
0
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1answer
68 views

Would the empirical behavior of a simple circuit match my model of it?

I have a practical problem in E&M which has baffled me and and my electrician. The copper water pipes in my house are carrying a current of small potential (~1V) AC current. Here is my ...
2
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1answer
93 views

How to homegrow large, momocrystalline water ice crystals

This is a follow up to this question:Can one get clear ice crystals from a dirty suspension?. How could one grow a large - meaning visible with the naked eye - water ice crstal with common household ...
5
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3answers
5k views

How do you build a nuclear reactor in your garage?

When I came across this link earlier today, I was astounded. Nuclear reactors are immensely complex devices that took scientists years to develop, and are usually housed in huge facilities. The link ...
5
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3answers
3k views

Atmospheric pressure experiment using a cup with a fluid to hold a glass plate

When I was in high school, my teacher did an experiment to show the power of atmospheric pressure. Experiment: Prepare a glass bottle, fill with water, put a glass plate on the bottle, make sure ...
3
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1answer
240 views

Easy to do experiments that clearly show outstanding properties of graphene

By chance we received for free some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires at our University. I would like to prepare some very easy to do experiments for the ...
5
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1answer
366 views

Physics of every-day life: rotating bag of tea

Whilst studying for my physics courses, I like to drink tea. Today, I noticed that if you pull a bag of tea out of a hot cup of water, it gradually starts to rotate, picking up speed as time ...
1
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0answers
205 views

Easy question about magnetism?

I have to build a simple electric motor by attaching a magnet to a battery, extending the terminals of the battery (with stiff wires so they could act as supports), and placing a coil of wire on top ...
7
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2answers
2k views

Is it viable or possible to make your own transistor?

Just wondering if it is possible/viable to construct your own transistor, not small like todays, but the same scale as the one created at Bell Labs.
2
votes
0answers
114 views

Calculate how hot PLA will become

I am trying to attach the shaft of a brass heating tip to a PLA component. My problem is that the tip will have to reach a temperature of about 200°C and the PLA can only handle a temperature of about ...
25
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6answers
7k views

How do whisky stones keep your drink cold?

From a discussion in the DMZ (security stack exchange's chat room - a place where food and drink are important topics) we began to question the difference between how ice and whisky stones work to ...
6
votes
2answers
187 views

Must a vertical sundial face exactly South?

I am a sundial. I'm prepared to bet Your watch can't tell when the sun will set I once heard Frank King talk about sundials in particular this very cool one, which measures Babylonian hours ...
4
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1answer
231 views

Michelson–Morley @ Home

The Michelson-Morley experiment seems to have taken many years, resources and a nervous breakdown to complete. Is it possible to recreate a variation of this experiment at home for say, under $1000, ...
1
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1answer
144 views

A good theoretical approximation for a magnetically damped pendulum

In a laboratory course we had to perform an experiment with a pendulum (just an iron weight on a wire) and play around for some time with its wire's length and so on. This was quite boring and we ...
3
votes
1answer
221 views

How to create visible reflections in shallow water?

Assumption: The only lights I have are candle, table lamp, and sunlight. What would I need to create visible reflection of an object in the shallow water contained in a 5 liter bucket? Is it even ...
3
votes
2answers
642 views

How does this trick with mirrors work?

Imagine two mirrors, set touching each other at right angles to one another. There is a 90 degree arc in which reflections can be seen, and a person standing in that arc can see himself reflected in ...
5
votes
1answer
394 views

Whistling on bottle tops

It is well known that if you blow horizontally on a bottle top it creates a sound. Pouring water to the bottle changes the pitch. I have been doing experiments on the relation between the sound's ...
1
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1answer
221 views

Why do CD's shatter in a microwave?

Why have I heard that eggs and CD's and DVD's explode when microwaved?
6
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3answers
309 views

How can I determine the coefficient $k$ in $ \dfrac{dT}{dt} = -k(T - 100 \mathrm{^\circ C}) $?

I recently spend some time on cooking and I'm curious about the time evolution of the temperature of the water. I did some experiment and the temperature is of the form $$ T = 100 \mathrm{^\circ C} + ...
9
votes
3answers
727 views

How hot is the water in the pot?

Question: How hot is the water in the pot? More precisely speaking, how can I get a temperature of the water as a function of time a priori? Background & My attempt: Recently I started spend ...
1
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1answer
705 views

Demonstrating Quantum effects with home experiments using green diode laser [closed]

I would like to preform home experiments to demonstrate quantum effects to my kids. I need a list of experiments on Laser photons that could be easily conducted at home to demonstrate quantum ...
4
votes
1answer
302 views

Accelerating onto and over inclined plane

Consider an RC car going off a jump. What angle is optimal to achieve the greatest distance? The height of each jump is the same. The angle of the jump and the related length of the jump changes. ...
0
votes
1answer
760 views

Experiment to measure initial speed of high speed tennis ball?

I want to devise a way to measure the initial speed of a tennis ball fired from a tennis ball cannon, but without using any speed-measuring devices. Just plan distance-measuring and physics formulas. ...
3
votes
6answers
10k views

Parallel circuits - Overall resistance decreases with additional resistor [closed]

Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
5
votes
1answer
322 views

Practical method to weigh human limbs with common household items?

What methods could be used to determine (or estimate within a reasonable margin of error) the mass of a living human's limbs, short of cutting them off? And more interestingly, how can this be done ...
1
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3answers
151 views

How to design an experiment that shows that a rectangular pulse can be expressed as a series of infinite sinusoids?

Is it possible to design a physical experiment that shows that a time limited signal, such as a rectangular pulse is composed of infinite continuous sine/cosine waves?
12
votes
3answers
7k views

Is it possible to reproduce Double-slit experiment by myself at home?

I want to reproduce this experiment by myself. What I need for this. What parameters of slits and laser/another light source it needs? Is it possible to make DIY-detector?
1
vote
1answer
441 views

Force exerted on a cone

This is probably a pretty elemental question, but I can't figure out what the concept is called or how to calculate it. Say you have a solid cone shaped piece of ice, you hold it in your hand and ...
6
votes
2answers
295 views

Is it cheaper to boil water on high gas heat or low gas heat?

Assume my time value is \$0. High gas heat adds more energy per second to the water but the pot may absorb the heat less efficiently, or maybe the shape of the flame is less good, or for other reasons ...
3
votes
2answers
234 views

Do I need to have an airtight container to siphon boiling water?

I'm attempting to siphon boiling water into another container for a school project. I have researched the physics of a siphon but I can't seem to make my boiling water siphon out of its initial pot. ...
4
votes
3answers
425 views

Room temperature and fan orientation [duplicate]

So I'm in a tiny dorm room and I normally point my fan blowing outside the window to cool my room off. I've been in some debates on blowing air out or in is more effective, so I'm hoping to get some ...
3
votes
1answer
392 views

Revealing Electric field lines through Grass seeds in mineral oil

In one of Walter Lewin's famous lectures, he takes a small container almost completely filled with mineral oil and grass seeds (I'll keep looking for the video to link to it). He connects two ...
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0answers
412 views

How much pressure is needed to break an egg if applied from top and bottom?

Everybody knows that you can't break an egg with our fingers when pushing from top and bottom. I assume if we could squeeze hard enough the egg would break?
2
votes
0answers
162 views

How can I determine the type of magnet used in a DC motor?

I repair electrical motors in a workshop and sometimes I must repair permanent magnet DC motors and other motors that use permanent magnets. I need to specify type of permanent magnet (Ferrite or ...
5
votes
1answer
368 views

Can you tell just from its gravity whether the Moon is above or below you?

If you are on a place of Earth where the Moon is currently directly above or directly below you, you experience a slightly reduced gravitational acceleration because of Moon's gravity. This is what ...
9
votes
4answers
8k views

What happens when you heat vodka in a microwave?

Since ethanol has a lower dielectric constant than water would the water heat up and boil before the ethanol? Would the water transfer heat to the ethanol and, since ethanol has a lower boiling point, ...
4
votes
1answer
80 views

Can I find the frequency generated by tapping a battery on a coin?

According To How Stuff Works , if you tap a 9 volt battery on a coin it will transmit Radio waves. I was wondering, because I don't have a radio with me at the moment, Is there a way I could discover ...
2
votes
3answers
932 views

Apparent paradox in equation of continuity

Equation of continuity says us that if we insert some fluid in a tube, the same amount of fluid will come out from the other end. If we make a small hole in a hose pipe, water will come out with a ...
3
votes
0answers
165 views

Why is a washing machine unable to spin-dry a duvet?

Background story: I put my duvet (synthetic filling) into a washing machine, and the machine was unable to spin-dry it. My mom told me: "It's because it is full of air". I was not satisfied with the ...
4
votes
2answers
184 views

Why don't Microwave ovens use more energetic EM radiation?

Because in theory, visible light contains more energy than the microwaves actually used to cook your food. 1) Does it have to do with resonance frequency of the $H_2O$ molecule? 2) How can ...
0
votes
1answer
162 views

Charging using a CRT TV set

I was doing an experiment with my CRT TV where I put aluminum foil on the screen wire it to a can and open the TV and a ring between 2 can will swing if I ground the other can. ...
3
votes
0answers
112 views

Thermal imaging camera [closed]

I'm making a tea bag experiment (Make a hollow cylindrical tube from light paper e.g. from an empty tea bag. When the top end of the cylinder is lit, it takes off.) I need to know how hot air is ...
2
votes
2answers
1k views

Liquid with freezing point above 0 Celsius that could be use at ice rinks

Please help me with an answer to my dilemma: Is there a liquid that could be used to fill an ice rink (non-explosive, non-poisonous, etc), and have the freezing point above 0 Celsius?
5
votes
1answer
557 views

Why does the milk frother on my coffee machine make so much noise?

I have a Sunbeam home espresso machine with a steam wand. The steam roars out straight from the end of the wand. When it's first placed in the cold milk it really screams! Once the milk has a bit of a ...